For use with Klenow. The reaction buffer, random hexamer primers,
and Klenow enzyme need to be added separately.

4a. Make the following mix:

Denatured DNA (10-25 ng)

9 ml

10X Klenow Reaction Buffer

2 ml

Random hexamer or octomer primer ( ~750 ng, 30 pmol)

2 ml

Klenow ( 5 units/ml )

1 ml

a-32P-dCTP

5 ml

5. Incubate at 37 °C for 10-60 minutes.

6. Stop the reaction by adding 1 ml of 0.5 M
EDTA or by heating heating to 95-100 °C for a couple of minutes.

7. Immediately before use in hybridization, denature the labeled DNA
by heating to 95-100 °C for 5 minutes and then put on ice.
To avoid poping up of the microcentrifuge tube, puncture a small hole
on the cap using a needle or use a microcentrifuge cap locker.